https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69650
--- Comment #47 from Roger Orr <rogero at howzatt dot demon.co.uk> --- Sorry, I wasn't clear enough. I'm unfortunately not at present able to post the whole source file. The file I posted *only* contains the line directives, so people can confirm whether there were any problems with them. (That file compiles fine for me too) There seems to be some interaction with some other part of the compilation, I'm trying to get a example I can post but this is proving troublesome.